The present invention relates generally to a headset for ambient noise suppression.
Noisy environments, such as those found in launch facilities and aircraft cockpits, can muffle critical voice communications and cause hearing loss if exposure is prolonged.
U.S. Pat. No. 2,043,416 to Lueg discloses a process of silencing sound oscillations in which the sound oscillations to be silenced are reproduced by a reproducing apparatus in the form of sound waves of an opposite phase, and then adjustable means cause the elimination of the two sound waves. A publication by Dr. Faux-Williams of Cambridge University entitled "A Review Lecture, Anti-Sound", Sept. 8, 1984 Proc. R. Soc. London A. Vol 395, pp. 63-88 (attached) discloses the principles by which acoustic and vibrational fields can be mimicked and cancelled by secondary sources. Also of interest are U.S. Pat. No. 2,972,018 to Hawley et al, U.S. Pat. No. 4,025,724 to Davidson, Jr. et al, and U.S. Pat. Nos. 4,153,815 and 4,417,098 to Chaplin et al.
An article entitled "Noise Canceling Headset System Undergoes Developmental Tests" in Aviation Week & Space Technology, Nov. 24, 1986, pp. 58-59, discloses an acoustic noise canceling headset system for use by military pilots. The system was developed by the Biological Acoustics Branch of the U.S. Air Force Aerospace Medical Research Laboratory and Bose Corp., and is described in a technical report AFAMRL-TR-84-008, titled Active Noise Reduction, by John Carter, available from the National Technical Information Service (NTIS) as AD-A139741.